Influences of dietary distillers dried grain level on growth performance,body composition and biochemical parameters of juvenile olive flounder (Paralichthys olivaceus)

This study was conducted to investigate the influence of dietary distillers dried grain (DDG) level on growth and body composition of juvenile olive flounder (Paralichthys olivaceus). Five diets (designated as DDG0, DDG7, DDG14, DDG21 and DDG28) were prepared to contain 0, 70, 140, 210 and 280 g kg^?1 DDG. Three replicate groups of fish averaging 11.6 ± 0.1 g were fed one of the diets for 8 weeks. Weight gain of fish fed diets containing 70–280 g kg^?1 DDG was not different to that of fish fed DDG0 diet (P > 0.05). Feed efficiency of fish fed DDG21 and DDG28 diets was lower than that of fish fed DDG0 diet (P < 0.05). The antioxidant enzyme and digestive enzyme activities were not affected by dietary DDG levels. The results of this experiment suggested that DDG is a valuable ingredient as a candidate to replace wheat flour in the diet and could be used up to 280 g kg^?1 for the growth of olive flounder. On the other hand, if lower feed efficiency of fish fed 210–280 g kg^?1 DDG is considered, up to 140 g kg^?1 DDG in diet is recommended for optimum feed utilization of fish.     

Differentiation of citrus bacterial canker strains in Korea by host range,rep-PCR fingerprinting and 16S rDNA analysis

Soil-borne cereal mosaic virus (SBCMV) causes a severe disease in susceptible cultivars of winter wheat. The virus is vectored by the soil-borne protist Polymyxa graminis. Experiments were conducted to investigate whether SBCMV RNA2 could persist in seed from SBCMV-infected susceptible cultivars of winter wheat. Over 7,000 seedlings were generated from seed collected from two cultivars of SBCMV-infected winter wheat. Seedlings were grown in a glasshouse compartment and batch tested for the presence of SBCMV using real-time RT-PCR. The majority of batches tested positive for SBCMV, indicating an RNA2 transmission rate of 1.8–9.4% in wheat. The presence of the virus was confirmed by amplifying and sequencing a larger (400 bp) fragment of viral RNA2 in a sub-set of the seedlings testing positive by real-time RT-PCR. Root extracts from this sub-set tested negative for P. graminis using real-time PCR. The implications for disease epidemiology of this virus are discussed. The authors are British Civil Servants and as such their work is subject to British Crown Copyright. This means the exclusive copyright for the article cannot be transferred.     

Molecular cloning and expression of caspase-3 in the protandrous cinnamon clownfish, Amphiprion melanopus, during sex change

The caspase-3 appears to be a key protease in the apoptotic pathway. We identified caspase-3 complementary DNAs from the ovaries of the protandrous cinnamon clownfish (Amphiprion melanopus), and investigated its mRNA and proteins, and activity levels during the sex change (I, mature male; II, male at 90 days after removing of the female; and III, mature female). The nucleotide sequence of the caspase-3 cDNA was 969 base pairs in length with open reading frames encoding peptides of 282 amino acids. The caspase-3 mRNA and protein, and activity levels in stages of the mature gonad are higher than those of the development gonad stage. To understand the effect of gonadotropin-releasing hormone (GnRH) on gonad apoptosis, we examined expression of genes caspase-3 mRNA and activity level in immature cinnamon clownfish gonads after GnRH analogue (GnRHa). The findings support the hypothesis that caspase-3 expression is associated with both testicular and ovarian development, and suggests that it may play a role in the control of ovarian development in cinnamon clownfish. Also, we demonstrate that GnRH agonists stimulate caspase-3 production which can in turn stimulate apoptosis. The present study provides a framework for better understanding of the role of caspase-3 during sex change processes in fish.     

Silsesquiazane/organic polymer blends as organic-inorganic hybrid materials

Silsesquiazane (SSQZ), one of the branched forms of polysilazane, was blended with polystyrene (PS), poly(methyl methacrylate) (PMMA), poly(iso-butyl methacrylate) (PBMA), and poly(vinyl acetate) (PVAc) to produce organic-inorganic hybrid materials. The polymers were selected to provide specific interaction, such as ??-?? interaction or hydrogen bonding, with SSQZ. AFM studies revealed that carbonyl containing polymers, PMMA, PBMA, and PVAc were miscible with SSQZ while PS was immiscible. DSC analysis of the hybrids also supported the miscibility behaviours of the system. The glass transition behaviour of SSQZ/PS showed individual transition temperature corresponding to the each component while SSQZ/carbonyl-containing polymers displayed one transition temperature that matched with the theoretically calculated values following the Kwei equation. Among the miscible hybrid system, the interaction with SSQZ increased in the order of PMMA> PBMA> PVAc, as determined by the q value in the Kwei equation. This result was confirmed by determining the degree of hydrogen bonding in FT-IR spectra. Thermal stability of organic polymers was improved by incorporating SSQZ regardless of the miscibility.     

Identification of Vibrio harveyi,Vibrio ichthyoenteri,and Photobacterium damselae isolated from olive flounder Paralichthys olivaceus in Korea by multiplex PCR developed using the rpoB gene

Major fish bacterial diseases in Korea are edwardsiellosis, streptococcosis, and vibriosis. Among vibrionaceae, Listonella anguillarum, Vibrio harveyi, V. ichthyoenteri, and Photobacterium damselae were identified as causative organisms of vibriosis in flounder. In this study, we developed a multiplex PCR method using the RNA polymerase β subunit (rpoB) gene, known as a housekeeping gene for identification of Vibrio spp. causing vibriosis in flounder. Three pairs of PCR primers were designed based on the rpoB sequence of three species, V. harveyi, V. ichthyoenteri, and P. damselae. The PCR assay, using a mixture of six primers, yielded amplicons of 601, 434, and 533 bp in V. harveyi, V. ichthyoenteri, and P. damselae. None of the untargeted species yielded an amplicon. The detection limits for pure culture in kidney were 2.5 × 10⁴ cfu/g kidney for V. harveyi, 2.5 × 10⁵ cfu/g kidney for V. ichthyoenteri, and 2.5 × 10⁶ cfu/g kidney for P. damselae. From the colonies on TCBS agar plates of different samples, 632 Vibrio spp. isolated from aquacultured flounder between 2004 and 2010 were identified by the multiplex PCR method. As a result, 265 strains (41.9 %) were V. ichthyoenteri; 115 strains (18.2 %) were V. harveyi and 72 strains (11.4 %) were P. damselae.     

Antioxidant Effect of Dietary Supplement Withania somnifera L. Reduce Blood Glucose Levels in Alloxan-Induced Diabetic Rats

The phenolic compounds and flavonoids were determined from the extracts of Withania somnifera root (WSREt) and leaf (WSLEt). The WSREt has 28.26 mg/g total phenolic compounds and 17.32 mg/g flavonoids, whereas WSLEt has 5.4 mg/g total phenolic compounds and 5.1 mg/g flavonoids. The WSREt, WSLEt and glibenclamide were orally administered daily to diabetic rats for 8 weeks. After the treatment, the levels of urine sugar, blood glucose, liver glycogen, and antioxidants like vitamin C and E in plasma and superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in liver, kidney and heart were determined. Diabetic rats showed a significant (p < 0.05) elevation in glucose and TBARS and a significant (p < 0.05) reduction in glycogen, vitamin C and E, SOD, CAT, GPx, GST, and GSH levels when compared to normal control rats. Administration of WSREt, WSLEt and glibenclamide to diabetic rats restored the levels to normal. In the light of aforesaid facts, it is suggested that the presence of phenolic compounds including flavonoids in W. somnifera root and leaf extracts and their antioxidant activity may play a vital role in reduction of blood glucose level in alloxan-induced diabetic rats.     

Suppression of pine wilt disease by an antibacterial agent,oxolinic acid

BACKGROUND: Pine wilt disease (PWD) is very complex and has been reported to be caused by pine wood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, and its accompanying bacteria. However, there is no report on the control of PWD by antibacterial agent. The present study was performed to investigate disease control efficacy of antibacterial agents against PWD. RESULTS: Among six antibacterial antibiotics tested, oxolinic acid (OA) showed the strongest antibacterial activity against five bacteria isolated from three strains of pine wood nematode. In in vivo assay, it effectively suppressed the development of PWD in three‐year‐old seedlings of Pinus densiflora Sieb. & Zucc.; it showed 71% control when injected at 3 mg per seedling. A mixture of OA and the nematicidal agent abamectin (Ab) showed higher disease control efficacy against PWD than either OA or Ab alone. In addition, OA alone and a mixture of OA and Ab also controlled PWD in approximately 20‐year‐old pine trees under field conditions. CONCLUSION: This is the first report on the suppression of PWD by OA. The result strongly indicates that PWD could be controlled by antibacterial antibiotic alone and a combination of antibacterial and nematicidal agents. Copyright © 2010 Society of Chemical Industry     

Effect of different girdling dates on tree growth,fruit characteristics and reserve accumulation in a late-maturing persimmon

Trunks of 8-year-old vigorous ‘Fuyu’ persimmon (Diospyros kaki Thunb.) were girdled to a 1 cm width on April 20 and June 10 2004. Tree growth and fruit characteristics were monitored for two years, with special emphasis on the carry-over effect in 2005. Girdling reduced trunk and shoot growth especially of April-girdled trees over two consecutive years. However, the most significant effect of girdling was in the occurrence of water sprouts: a control tree had 29.5 in 2004 and 27.3 in 2005, whereas the April-girdled trees had only 0.3 and 5.3, respectively. Girdling increased fruit set by nearly 50% and enhanced fruit colour in 2004 only. Girdling date did not significantly affect fruit size and soluble solids for two years. Fruit flesh of girdled trees in 2004, especially in the April-girdled trees, had lower N and P concentrations. The levels of starch, soluble sugars, and inorganic elements in flower-bearing distal buds measured just before new growth in 2005 were not significantly altered by the girdling in 2004.     

Rose (Rosa hybrida L.) EST-derived microsatellite markers and their transferability to strawberry (Fragaria spp.)

The ‘Genome database for Rosaceae (GDR)’ provides a large collection of expressed sequence tags (ESTs) harboring simple sequence repeats (SSRs) from several Rosaceae genera, including Rosa (rose). Primer pairs flanking SSR were designed for 312 unique Rosa ESTs based on GDR database. Eight rose (Rosa hybrida L.) genotypes were tested for PCR amplification, and 287 (92%) of the primer pairs generated allele-specific PCR bands that were readily scored. From 183 (63.7%) primer pairs that evidenced polymorphic alleles among the eight rose cultivars, 20 pairs evidencing EST sequence homology to known gene functions and high levels of polymorphism were selected and utilized for DNA fingerprinting and genetic diversity assessments of 47 rose hybrids. A total of 202 polymorphic bands were scored and generated unique fingerprints for each rose hybrid. The Nei–Li genetic similarity coefficients among 1081 pair-wise comparisons of 47 cultivars exhibited a broad range of genetic variations from 0.30 (‘Grand King’ and ‘Carnival’) to 0.99 (‘First Red’ and ‘Red Champ’). UPGMA cluster analysis divided 47 hybrids into five major groups and two sub-groups. The cross-species transferability of 273 EST-SSR primer pairs was evaluated using four genotypes of the strawberry, a genus member of the Rosaceae family. PCRs on the DNA samples of strawberry were successful for 165 primer pairs; among these, 123 pairs amplified 243 polymorphic bands. As surrogates of the marker transfer, the phenetic relationship among the four strawberry genotypes was evaluated. Genetic similarity coefficients varied from 0.78 (‘Maehyang’ and ‘Janghyee’) to 0.64 (‘Janghyee’ and ‘Pragana’). The results of cluster analysis showed that the three octaploid strawberry cultivars were quite similar, whereas the diploid ‘Pragana’ was related distantly at the genomic DNA level. The EST-SSR markers developed in the present study can be efficiently utilized for genetic diversity studies in Rosaceae.